Process of and means for nickel plating



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nnvvrar n name, or am PROCESS OF AND MEANS FOR PLATING.

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of and Means for Nickel Plating, of-which.

the following is a full, clear, and exact description.

This invention relates to a process of and means for electro-plating, and more particularly to the application to articles, such as spring bars or plates, a hard, dense and finely-divided crystalline deposit of nickel, which deposit will adhere firmly to the plates or other articles to which .it is applied and which will withstand all of the ordinary incidents of use, including a. bufiing operation, without being readily cut or worn away lltt . no thereby. A further object of the invention is .to accomplish the electroplating of articles" at a speed greatly in excess of that which has been obtainable heretofore. Other and more a limited objects of the invention will appear hereinafter, "and will be realized in and through the steps and combinations thereof embodied in theclaims forming part hereof.

In the practice of my process, as used for the nickel plating of steel bars or plates, such as are employed in the manufacture of vehicle springs and bumpers, the'plates are first thoroughly cleaned in any approved manner, as by a polishing. treatment; and then immersed in a special, heated nickelplating bath having special nickel electrodes,

through which electric current is passed under a very high amperage as compared with Appl1cat11on filed January 5, 1923. Serial Ito. 610,927.

are employed, in about the proportions stats ed, for'each gallon of solution:

32 oz. nickel sulphate (NiSO,.7H,O)

3.3 oz. nickel chloride (NiGl,.6H,O)

2 oz. boric acid (H BO While the proportions stated may be varied somewhat, with comparable results, those given are best adaptedfor successful results. The solution is heated (as by means of a steam coil) to a temperature of from 65 C. to 90 (1., the best results having been obtained hitherto by employing a temperature of about 85 C. For the anodes, I employ substantially pure nickel (at least 99% pure). In order to obtain this purity it is preferable to employ, and I do employ, electrolytic nickel, althou h any form of very pure nickel (over 99% would give satisfactory results.

With a bath constituted and heated in the manner described, and employingsuch pure nickel anodes, I preferably employ, for the plating work, current at a density of approximately 100 amperes per square foot of metal treated, as distinguished from the ordinary practice wherein a current density WOW, MICHIGAN,j ASSIGJNOR T0 CHRISTIAN GIRL, 0F

KALAMAZOO, MICHIGAN.

of 3 to 7 amperes per square foot is employed. Howevenmany good results may .thigggh, as by friction in ordinary use or in After the initial nickel-treating operation, the bars or plates are'placed in a copper plating bath, the bath containing the follow- 1ng ingredients, preferably in about the proportions stated, per gallon of solution 28 oz. of copper sulphate (CuSO,.5H,O) 11 oz. of'sulphuric acid (H SOJ.

' The copper-plating solution is used at a temperature "of preferably 30 0., employing approximately the same electric current density as is the case in the nickel plating operation. In order to secure an efi'ective copper-plating at this current density, it is necessary that the solution be vigorously agitated, and this agitation is accomplished by means of air, which may be introduced- While the proportions'hereinbefore set forth for the copper sulphate and the sulphuric acid per gallon of solution are those which are preferred, a considerable latitude in such proportions is permissible. For instance, the copper sulphate may vary from 25 to 35 oz. per gallon and the sulphuric acid from 3 to 12 oz. per gallon, without materially changing the nature of the copper-plating. Furthermore, a fairly satisfactory result as to plating may be obtained under a wide variation of current densityfro1n 2 or 3 amperes to 200 amperes per square foot. However, the plating secured at the low current density will be quite soft and the time consumed in such operation will be excessive. The temperature also maybe varied from 20 C. to about 50 C. with very satisfactory results. However, the best results are obtained by using the proportions of bath-ingredients, the temperature, and the current density set forth hereinbefore. By so doing, a hard, dense and adhesive coating is secured, the operation requires but a very short time as compared with that re uired in ordinary copper-plating practice an produces a much smoother coating than is obtained in ordinary practice, usually rendering unnecessary a buifing operation prior to the final nickel-platin operation.

After the copper-p ating treatment, the bars or plates may be buffed to insure a smooth surface for the final-nickel coating.

This final coating is applied in the same manner as the first coating or plating. After the final nickel-plating operation, the bars or lates may be buffed.

he practical advantages of the process herein described are that I am enabled greatly to improve the character of the coating applied to thebarsor plates and to effect a great reduction in the time required for effecting such coating. The coating is made up of a hard, dense, and very-finely divided crystalline deposit of nickel which adheres firmly to the articles coated and which withstands, to a marked degree, bufling operations and the ordinary incidents of use. The coating is much harder than that which'is secured by ordinary nickel plating o erations, and this hardness and density e time the wear-and-rust-resistant qualities of the coat ing. Another and very imIportant advantage of my process is t at am enabled to re uce the time for completely plating the plates or bars to about one thirtieth that which is ordinarily required for this purpose.

The employment of a heated bath with high current-density enables me to plate with great rapidity and to employ for this purpose substantially pure nickel for the anodes. The use of such nickel results in a deposit of substantially pure nickel upon the cathodes and in maintaining the bath substantially free from sludge. The presence of a chloride or chlorides in the bath facilitates both the speed of the plating-operation and the quality ofthe nickel deposit.

Also, by the employment of "a chloride 1n the bath, the time required for the plating operation is greatly shortened and, if nickel chloride be used as well as nickel sulphate, the bath will be substantially free from all metal or ammonium salts and will contain practically no other salts than those of nickel.

Having thus described my invention, what I claim is:

1. The process of nickel-plating articles which comprises the following steps:

(a) Subjecting the articlesto an electroplating treatment, employing therein anodes of substantially pure nickel, a current density of approximately 100 amperes per square foot of metal treated,'and a bath heated to about C. and containin the following ingrediments, in substantially the proportions stated, per gallon of solutionc 32 oz. nickel sulphate (NiSOflI-LO) 3.3 oz. nickel chloride (gNiCl tH O) 2 oz. 'boric acid (H 13 (b) Subjecting the said articles to a copper-plating treatment in a bath agitated with air and at a temperature of approximately 30 (3., said bath containing the following ingredients in approximately the proportions stated per gallon:

28 oz. of copper sulphate (CuSO .5H,)

11 oz. of sulphuric acid (H SO -(c) Nickel-plating the articles in substantially the same manner and in a bath of the same character as set forth in step (a) hereinbefore.

2. The process of nickel-plating articles which-comprises the following steps:

(a) subjecting the articles'to an'electroplating treatment, employing therein anodes of substantially pure nickel, a current density not materially less than 50 amperes per square foot of metal treated, and a heated bath containing the following ingredients, in substantially the proportions stated, per gallon of solution:

32 oz. nickel sulphate (NiSO .7H O) 3.3 oz. nickel chloride (NiCl. ,.6H,O)

2 oz'. boric acid (H BO (b) subjecting the said articles to a copper-plating treatment in an agitated bath containing the following ingredients, in ap-' proximately the proportions stated, per gal- 28 oz. copper sulphate (C11SO .5H,)

11 oz. sulphuric acid ('H,SO,).

(c) Nickel-plating the articles in substantially the same manner and in a bath of teoaaoc the same character as employed in the former nickel-plating operation.

3. The process of nickel-plating articles which comprises the following steps:

(a) Nickel-plating the articles in a heated bath, employing therewith substantially pure nickel anodes and a current density not materially less than 50 amperes per square foot of metal treated;

(b) Coppenplating the articles in a suitable bath under high current density, with the agitation of such bath;

0) Nickel-plating the articles thus treated in substantially the same manner as employed for the first operation.

4. The process of nickel-plating articles which comprises the following steps:

(a) Nickel-plating the articles in a heated bath, employing therewith substantially pure nickel anodes and a current density of not materially less than 50 amperes per square foot of metal treated;

(b) Copper-plating the articles in a suitable bath;

(0) Nickel-plating the articles thus treated in substantially the same manner as employed for the first operation.

5. The process of nickel-plating articles -which comprises the following steps:

(a) Nickel-plating the articles in a heateol solution of nickel sulphate, nickel chloride, and boric acid, with the employment of an electric current of high density;

(b) Copper-plating the articles in a solution of copper sulphate and sulphuric acid, P

subjected to agitation, and with the employment of an electric current of high density;

(c) Subjecting the copper-plated articles to a nickel-plating operation similar to that employed-for the first operation.

6. The process of nickel-plating articles which comprises the following steps:

(a) Nickel-plating the articles in a heated bath and with the employment of substantially pure nickel anodes and an electric current of high density;

(6) Copper-plating the articles in a bath subjected to agitation and with the employment of an electric current of high density;

(0) subjecting the copper-plated articles to a nickel-plating operation similar to that first described.

7. The process of nickel-plating articles which comprises the following steps:

(a) Nickel-plating the articles in a heated bath containing a chloridein solution and with the employment of substantially pure nickel for the anode or anodes and an electric current of high density.

(6) Copper plating the articles in a bath subjected to agitation and with the employment of an electric current of high density.

ticle.

(a) Nickel-plating the copper-plated ar- 8. The process of nickel-plating articles which comprises the following steps:

(a) Nickel-plating the articles in a heated bath containing nickel chloride in solution and with the employment of substantially pure nickel for the anode or anodes and an electric current of high densit (6) Copper-plating the articles in a bath subjected to agitation and with the employment of an electric current of high density.

(0) Subjecting the copper-plated articles to a nickel-plating operation preferably similarto that employed for the first operation.

9. The process of nickel-plating articles which comprises the following steps:

(a) Nickel-plating the articles in a heated bath containing a chloride and with the employment of substantially pure nickel for the anode or anodes and an electric current of high density.

(b) Copper-plating the articles in a bath subjected to agltation by air under pressure introduced below the surface of the bath and with the employment of an electric current of high density.

(0) Nickel-plating the articles thus copper-plated and preferably by means of a nickel-plating operation similar to that employed for the first operation.

10. The process of nickel-plating articles which comprises the following steps:

(a) Nickel-plating the articles.

(b)d Copper-plating the articles thus nickel a e (c) Nickel-plating the articles in a heated bath containing nickel chloride in solution and with the employment of substantially pure nickel for the anode or anodes and an electric current of high density.

11. The process of nickel-plating articles which comprises the following steps:

(a) Nickel-plating the articles.

(1)) Copper-plating the articles in a bath subjected to agitation and with the employment of electric current of high density.

(a) Nickel-plating the articles in a heated bath containing nickel chloride in solution and with the employment of substantially pure nickel for the anode or anodes and an electric current of high density.

12. The process of nickel-plating articles which comprises the following steps:

(a) Nickel-plating the articles.

(6) Coppenplating the articles in a bath subjected to agitation by air under pressure introduced below the surface of the bath and with the employment of an electric current of high density.

(a) Nickel-plating the articles thus copperlated.

In testimony EDWIN M. BAKER. 

